Admiral's Between Decks
A discreet seaman's term used to convey that male on male anal sex activity is transpiring between two or more sailors on the same ship.
Captain: Yeoman, where is the first mate? He's been gone for an hour. And where are those new young cadets?
Yeoman: Captain, The Admiral's Between Decks.
Captain: Aye! Plundering again.
Yeoman: Captain, The Admiral's Between Decks.
Captain: Aye! Plundering again.